Because of the weight of my robot I had to change my power system from 12v to 24v. In doing so I had to make room for larger motors and an additional car battery. This has caused a redesign of my robot leg section which has some new engineering challenges. The soil sampler will no longer fit as designed by Mike Joyce. The AC power supplies will no longer fit in the upper leg section becasue the additional battery will need to go in the same location and So my machinist and I will have to redesign it. We will probably use a variation of the screw driver approach, but more on that later.
I changed my motors to the NPC BR81 and Br82 motors with the same rubber wheels I had on my original drive unit. The are 24V 182 RPM and can easily move 550 lbs (so long as your robot is less than 300 lbs the original drive section will work just fine).
These motors can be obtained direct from NPC or you can get them from the RobotMarketplace.com. However, modifications to these motors are necessary! Brake removed, length shortened and gear plate replaced with drive section bottom plate. It was dissapointing that I couldnt find any motors strong enough that could be installed in a plug and play fashion. Below is a picture of the batteries I use.
Don’t let the tape worry you. It was just a temporary modification to ensure fitment.
Here is the final version of the new drive section & battery compartment:

OK, what you see before you is the complete lower assembly (well I have my side plates off currently) of my B9. I am very proud of this. It was a lot of work (and money) to get to this point. But like the man said, a B9 is never truly finished until I say it is (ahem…or maybe the wife has a say in it???) Anyhow, I decided to put him on a scale. WOW … what a surprise! From the waist down he was 300 lbs. For comparison, Mike Joyce’s entire replica robot weighs in at approximately 275. That presents a huge problem for me.

With a projected weight of my robot now at over 400 lbs the current motors will not perform very well so that means I need to redesign the drive section with more powerful motors and that means just 1 thing ……. you guessed it, bigger; more powerful motors need bigger or more batteries. So I am changing the electrical system from a 12V system to a 24V system.

I will also have to redo the drive section and try to lighten all metal surfaces as much as possible. This will not be cheap….

I did some additional changes to the articulating hip and leg assembly. I made the back area narrower as well and I did a re-orientation of the base plate for better wire feeding throughout the endoskeleton. In addition, standoffs were drilled and tapped for controller placements and wire feeding. I used patterns for an insulated standoff for the Vantec Controllers I will be using. I also made some changes to the torso rotation motor and mount. I will be using the RDFR23 for the foot drives and 1 RET411P for the hip motor and 1 RET411H for the Torso rotation motor. Instead of the friction wheel rotation method used by Mike, I will be re-orienting the motor and installing a hub and extra large gear for a very fast rotation direct drive so I can more precisely control the speed and whip around as seen in the series when Bob May would spin the torso around quickly. Speaking of Torso’s……. I also received the Replica Torso from Mike Joyce. I had purchased the club standard torso and had it professionally prepared by Richie. It was awesome but when I took it to be professionally painted the shop that did it used the wrong paint and solvent. The Torso started to melt. In their haste they tried to fix it but made it even worse so it was a total loss. A 2500 loss. Ouch!
So I am starting over again with a new torso and donut. As you can see to the left there is a side by side comparison of the club vs. the replica torso. This will present some new and additional challenges in that the replica torso is smaller so other items like the collar, vents, donut and neon base plate may require additional fitment. Only time will tell if I will need to make new components or if the smaller torso size will even be noticeable with existing parts. The Replica torso is the black one. The club standard is the gray one.

Also, here is the drive section that I created. This baby hauls a lot of weight (over 330 lbs) at parade speed with ease. It is smooth on acceleration and deceleration. For those who don’t know what that blue thing is on top of it, that is the infamous Mike Joyce Replica Soil Sampler (no longer available). All of this stuff fits inside of the tread sections. I will be redesigning the soil sampler so members will have an option later on.